Dr. Reite's main research interest is a study of the basic behavioral and physiological correlates of separation and loss in macaque monkeys. He anticipates that the results of his studies will lead to an improved understanding of the physiology of loss separation and the development of a comprehensive pathophysiology of grief. During the past several years he has developed, in collaboration with electronic and computer engineers and others, a sophisticated array of techniques to apply to this problem. He is using a surgically-implanted biotelemetry system to monitor multivariable physiological data from unrestrained monkey infants. He thus is able to monitor physiological functions without the complicating factor of effects which could be due to handling the monkeys during the assay procedures. A major goal during the past 3 years was to develop a Biobehavioral Development Profile (BDP) for the pigtailed macaque monkey which will permit continuous developmental assessment of individual monkeys across a number of areas. Much of the research to date has focused on technological developement, but there have been some interesting findings of changes in behavioral and physiological correlates immediately following and during infant-mother separation. The proposal itemizes specific aims designed to carry these studies further. In addition, an evaluation of the effect of maternal separation on immune function is planned in collaboration with Dr. Zimmerman in the Department of Medicine. Another aim is to determine to what extent the physiological correlates of separation found in pigtailed macaque infants are also seen in other primate species. The species to be used is the bonnet macaque. This experiment is designed in part to test whether information on the pigtail infants can be generalized to other primate species.